Dwain Chambers clocks his fastest time in five years

Chambers ran 10.06sec, his fastest time since 2003 and an effort that puts him level with Tyrone Edgar at the top of the British rankings.

Olympics aim: Dwain Chambers (centre)

The sprinter's lawyers will now file an action against the British Olympic Association in the High Court in a bid to overturn the lifetime ban that currently excludes Chambers from the British team after he admitted taking banned drugs, an offence for which he has already served a two-year ban.

Chambers said last night: 'Now I've got the qualifying time, I've just got to continue competing and let the lawyers do their part.

'It's only a matter of time before I will be able to show what I can do when I get into the Olympic final. I will always remain a clean athlete from here onwards.

'I was concerned with getting the qualifying time. That was playing on my mind a bit.'

Now, with Chambers clearly in excellent form, Britain's Olympic trials in two weeks' time are likely to be dominated by his legal battle.

In what will be a race against time, Chambers' lawyer, Nick Collins, will file an action this week and ask for a High Court hearing in the next fortnight to overturn the BOA ban.

Chambers needs to act fast as the British team cannot be changed after July 20.

Competing yesterday in the tiny town of Biberach, in the heart of the Black Forest, Chambers again demonstrated his ability to dominate British sprinting.

The reformed drugs cheat, who has admitted using a cocktail of performance-enhancing substances, including steroids, bloodboosting EPO and human growth hormone from 2002 until 2003, cruised through the heats in 10.14sec before easily winning the final in 10.07.

That form means he is a likely winner of the July 12 trials, which would put him in prime position to be selected for Beijing if he were to overturn the ban.

It was well inside the required time of 10.21 and among Britons, only Tyrone Edgar has run faster this season, in 10.06.

After being barred from major European meetings because of a ban on drug cheats, Chambers has struggled to find high-class meetings and yesterday was the first time he had competed in what might be considered to be ideal conditions.

Chambers' attention will now focus on his legal battle to overturn the ban imposed on him by the BOA, the only national Olympic association who refuse to pick athletes found guilty of a serious doping offence.

Others, such as Christine Ohuruogu, who have committed lesser offences, are initially banned but normally cleared on appeal. Chambers' offence was deemed to be so grave that there is no chance that he would be cleared to run under current BOA rules.

Collins will argue that the ban is unfair as Chambers has already been punished with a two-year ban by the International Association of Athletics Federations.

Chambers also has to pay back a proportion of the prize money he won in 2002 and 2003.

Collins was hoping that the BOA would agree to a date before the trials. But it is understood that the BOA will take a belligerent stance and are not interested in working with Collins to agree a convenient date.

The build-up to the trials will now mirror the controversy that surrounded the world indoor athletics championship, when Chambers won the trials and, having fulfilled the selection criteria, effectively forced UK Athletics to pick him for the team against their will.